Issue 06

Clinical Question

How many ileal pouch-anal anastomosis (IPAA) patients develop Crohn’s disease of the pouch?

Editor’s Bottom Line

Crohn’s disease (CD) arises in 1 of 10 patients undergoing pouch construction for ulcerative or indeterminate colitis, but we need to standardize criteria for its diagnosis.

Reference

Barnes EL, Kochar B, Jessup HR, et al. The Incidence and Definition of Crohn’s Disease of the Pouch: A Systematic Review and Meta-analysis. Inflamm Bowel Dis. E-pub ahead of print Jan 30, 2019; https://doi.org/10.1093/ibd/izz005

Synopsis

The incidence of CD of the pouch in patients who have undergone IPAA for ulcerative colitis (UC) is unclear, partly because criteria for its diagnosis vary. In this study, researchers at the University of North Carolina at Chapel Hill analyzed 12 studies published through March 1, 2018 to document rates of this complication as well as to identify common diagnostic criteria. The studies included 4,843 patients who had undergone IPAA for UC or indeterminate colitis (IC).

In a pooled analysis, the incidence of CD of the pouch was 10.3%, with rates ranging from 3.1% to 21.3%. An analysis excluding studies with IC patients found a pooled incidence of CD of the pouch was 12.4%. Studies published more recently tended to report higher rates.

The mean time to diagnosis of CD of the pouch, in two studies that reported this parameter, was 17 to 20 months.

The most common diagnostic criteria for CD of the pouch included the presence of one or more fistulae, one or more strictures involving the pouch or the pre-pouch ileum, and/or ileal inflammation above the pouch. The authors said these features could be used as the basis for a “uniform set of diagnostic criteria” for CD of the pouch.

Details

Study Design: Systematic literature review
Funding: The National Institutes of Health, the Nickolas Bunn Boddie, Sr., and Lucy Mayo Boddie Foundation and the Crohn’s and Colitis Foundation
Allocation: Not applicable
Setting: Review of single-center longitudinal cohort studies
Level of Evidence: 1a (Oxford Levels of Evidence)

The summary and conclusion in this issue of E-mentoring in IBD pertains to the manuscript(s) being reviewed, and should be considered in the context of what is already known surrounding the topic and incorporated into practice as deemed appropriate by the individual learner.